Exhaust studs and other questions

[Roostabunny]

Hey all, did some searching and did find quite the answers I needed. Lemme know what you think.

Undertook some exhaust repairs (a small hole in each of the #2 and #3 header pipes where they connect to the crossover). Worked well, but I think the teardown and rebuild disrupted the sketchy seal I had on my #3 exhaust port.

I inherited a broken-off bolt and a #3 flange being held on by the remaining bolt, and discovered it when the flange rattled loose one day years ago. I bought new bolts, but when I tried to install them I discovered that the lower hole had a combination of 3/4" or so of stripped threads and then what I believe is the rest of an original bolt. I got it to seal with one bolt and kept an eye on it for a while.

But, after giving the exhaust a once-over, it was in much better shape than I expected (let's hear it for the Arizona weather this bike spent its first 25 years in) so I want to finish fixing things right. Then I figure I'll also get better results from setting my mixture and syncing.

So here are my questions...

1.) This is a job for a helicoil, right? Do I have to get the rest of that bolt out, or can I tap the part that's open and install a short coil?

2.) I'm reading (and mechanical friends are telling me) I need to install studs. I found this tread http://www.thegsresources.com/_forum/showthread.php?t=172346&highlight=exhaust+studs that mentioned the following about a NAPA kit that “Includes 10 M8x1.25x62mm studs and 10 nuts.”, but the link was broken and I couldn’t find stud kits on the NAPA site. Any tips on specs and a source for my GS850?

3.) The studs get sealed in with high heat loctite? #567, #620, #272? So many options!


4.) I think I can reuse the exhaust gaskets, but I wanted to check.

5.) Am I dense, or is there no way to remove the exhaust flange from the outer pipes? It was so nice cleaning up the middle two on a bench mounted brass wire wheel, but I can go to the pipes if that’s the only option.

Thanks, as always!

 

[cowboyup3371]

You can find some decent studs at Ace hardware

 

[Suzuki mad]

With 3/4 of the old bolt still in there somebody is going to have to drill that out so you can helicoil. You could try a short coil but what if that doesn't work. Head off and down to an engineers for spark erosion at worst.

Studs are easier but well lubricated bolts come out just as easy. I'd use car head ones and copper nuts.

Dont know what you would seal them in with. Over time the aluminium would grow onto the studs and hold them tight.

I wouldn't re-use the crush gaskets but you can try.

Dont know how the flanges come off other than by cutting.